file.h

// Copyright 2014 Google Inc. All rights reserved.
//
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file or at
// https://developers.google.com/open-source/licenses/bsd
 
#ifndef PACKAGER_FILE_FILE_H_
#define PACKAGER_FILE_FILE_H_
 
#include <stdint.h>
 
#include <string>
 
#include "packager/base/macros.h"
#include "packager/file/public/buffer_callback_params.h"
 
namespace shaka {
 
extern const char* kCallbackFilePrefix;
extern const char* kLocalFilePrefix;
extern const char* kMemoryFilePrefix;
extern const char* kUdpFilePrefix;
extern const char* kHttpFilePrefix;
const int64_t kWholeFile = -1;
 
class File {
 public:
  static File* Open(const char* file_name, const char* mode);
 
  static File* OpenWithNoBuffering(const char* file_name, const char* mode);
 
  static bool Delete(const char* file_name);
 
  virtual bool Close() = 0;
 
  virtual int64_t Read(void* buffer, uint64_t length) = 0;
 
  virtual int64_t Write(const void* buffer, uint64_t length) = 0;
 
  virtual int64_t Size() = 0;
 
  virtual bool Flush() = 0;
 
  virtual bool Seek(uint64_t position) = 0;
 
  virtual bool Tell(uint64_t* position) = 0;
 
  const std::string& file_name() const { return file_name_; }
 
  // ************************************************************
  // * Static Methods: File-on-the-filesystem status
  // ************************************************************
 
  static int64_t GetFileSize(const char* file_name);
 
  static bool ReadFileToString(const char* file_name, std::string* contents);
 
  static bool WriteStringToFile(const char* file_name,
                                const std::string& contents);
 
  static bool WriteFileAtomically(const char* file_name,
                                  const std::string& contents);
 
  static bool Copy(const char* from_file_name, const char* to_file_name);
 
  static int64_t CopyFile(File* source, File* destination);
 
  static int64_t CopyFile(File* source, File* destination, int64_t max_copy);
 
  static bool IsLocalRegularFile(const char* file_name);
 
  static std::string MakeCallbackFileName(
      const BufferCallbackParams& callback_params,
      const std::string& name);
 
  static bool ParseCallbackFileName(
      const std::string& callback_file_name,
      const BufferCallbackParams** callback_params,
      std::string* name);
 
 protected:
  explicit File(const std::string& file_name) : file_name_(file_name) {}
  virtual ~File() {}
 
  virtual bool Open() = 0;
 
 private:
  friend class ThreadedIoFile;
 
  // This is a file factory method, it creates a proper file, e.g.
  // LocalFile, MemFile based on prefix.
  static File* Create(const char* file_name, const char* mode);
 
  static File* CreateInternalFile(const char* file_name, const char* mode);
 
  // Note that the file type prefix has been stripped off.
  std::string file_name_;
 
  DISALLOW_COPY_AND_ASSIGN(File);
};
 
}  // namespace shaka
 
#endif  // PACKAGER_FILE_FILE_H_